Standardized, integrally stiffened, structural shapes, fabricated by the extrusion of ductile metal have long been known in the structural art. However, such structures or shapes, fabricated by the lamination and resin polymerization or curing of resinous, filament reinforced, composite materials have only recently evolved. A drawback to their use however has been the problem of incipient peel or the tendency for stress forces to cause one part of the structure to be peeled away from an adjacent portion of structure. Therefore, it has been found desirable by the invention herein to provide lightweight, high strength, integrally stiffened, structural shapes which are peel proof or peel inhibited, to thus be particularly useful in the construction of integrally stiffened components for aircraft, missiles and space vehicles.